US Patent 7469712 Relief valve

A valve for the fuel system of a turbine engine works to relieve high pressure transients in the liquid fuel side of the turbine engine arising from the elevated ambient temperatures of operation of the turbine on gaseous fuel. The valve also prevents significant pressure losses during turbine start-up and sustained operation. The valve is bi-stable and has a liquid fuel driven poppet that toggles between one of two closed positions to interrupt flow through the valve when below a lower pressure limit and when above an upper pressure limit. The poppet moves to an intermediate position temporarily to permit pressure relief. A method of operating such a valve is also provided.